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1
Cougo, França Bernardo. "Design and Optimization of InterCell Transformers for Parallel MultiCell Converters." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0057/document.
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Les convertisseurs multicellulaires parallèles permettent de traiter des puissances importantes et de profiter d'une certaine standardisation des équipements. Ces dernières années, ces structures ont connu un regain d'intérêt lié notamment à la possibilité de couplage magnétique des inductances. Ce couplage aboutit à un composant magnétique aux propriétés très différentes appelé Transformateur Inter-Cellules (ICT) ; il ne modifie pas le courant de sortie, par contre il réduit l'ondulation de courant dans les bobines et l'ondulation de flux dans certaines parties du noyau. On peut montrer que ce couplage entraîne une réduction des pertes Joules dans les conducteurs et des pertes magnétiques dans le noyau. La réduction de l'ondulation de courant diminue également le courant efficace dans les semiconducteurs ce qui réduit les pertes par conduction, et la différence entre le courant à l'amorçage et au blocage des interrupteurs, ce qui permet la diminution des pertes dans les semiconducteurs lorsque les pertes au blocage sont supérieures aux pertes à l'amorçage. Le dimensionnement d'un ICT n'est pas fondamentalement différent de celui fait pour d'autres composants magnétiques en ce sens qu'il est basé sur le respect de certaines valeurs limites (induction, température) ce qui suppose une évaluation des différentes pertes et l'élaboration d'un modèle thermique. Par contre, la manière d'évaluer ces différentes grandeurs est tout à fait spécifique et n'a que quelques points communs avec les méthodes de calcul des inductances et des transformateurs Dans ce travail de thèse, on montre comment dimensionner ces ICTs en considérant plusieurs topologies et méthodes différentes, correspondant à différents niveaux de sophistication et de complexité. L'explication de ce dimensionnement est divisée en quatre parties : Pertes Cuivre, Pertes Fer, Densité de Flux de Saturation et Aspects Thermiques. L'évaluation des pertes cuivre liées aux composantes alternatives des ICTs constituent un point particulièrement délicat dans la mesure où elles résultent de la combinaison de deux facteurs eux-mêmes difficiles à évaluer ; l'inductance de fuite qui détermine l'amplitude des courants alternatifs mais dépend des flux principalement non canalisés et circulant dans l'air (volume d'étude important, effets 3D…), et la résistance équivalente des bobinages qui en haute fréquence est sujette à des phénomènes complexes comme les effets de peau et de proximité. En se basant sur l'utilisation d'un logiciel simple mais néanmoins robuste et fiable pour calculer précisément les résistances en haute fréquence et les inductances de fuite des ICTs, plusieurs astuces permettant de réduire les pertes cuivre non seulement des ICTs mais aussi des transformateurs et des inductances sont suggérées. Des tableaux simples sont développés pour aider le concepteur de transformateurs à identifier la meilleur configuration de conducteurs dans une fenêtre de bobinage en prenant en compte la forme d'onde du courant, le nombre de tours des enroulements, la fréquence des courants et les paramètres géométriques. Des formules analytiques et des outils de calcul adéquats ont ensuite été utilisés pour développer des routines d'optimisation ayant pour but la réduction de la masse, du volume, des pertes ou du coût des ICTs. Des interpolations multidimensionnelles des valeurs présimulées des résistances et inductances de fuite en haute fréquence sont utilisées afin de réduire le temps d'exécution de la routine d'optimisation. Plusieurs dimensionnements des ICTs ont été comparées vis-à-vis des matériaux du noyau et des conducteurs, du nombre de cellules de commutation et de la fréquence de découpage. Des comparaisons avec des selfs ont également été faites afin de montrer les avantages de ces ICTs. Des aspects de la commande des convertisseurs multi-niveaux triphasés ont également été étudiés vis-à- is du flux circulant dans les ICTs. Des homopolaires, spécifiques pour chaque stratégie MLI et chaque topologie convertisseur/charge, sont créées afin de minimiser le flux dans les ICTs et par conséquent de réduire davantage la masse et la taille de ces composants. Des comparaisons entre différentes méthodes de MLI sont effectuées et vérifiées expérimentalement<br>In recent years, the interest for parallel multicell converters has grown, which is partially due to the possibility of coupling the inductors used to connect the different commutation cells together. Coupling the inductors to form an InterCell Transformer (ICT) does not usually modify the output current, but it reduces the current ripple in the windings and the flux swing in some regions of the core. It can be shown that this brings a reduction of copper and core losses in the magnetic component. The reduction of the phase current ripple also reduces the difference between turn on and turn off current in the switches, which brings a reduction of switching losses for devices generating more losses at turn off than at turn on. The design of an ICT is not that different from any other magnetic component but it is very specific and inherent features must be taken into account. Taking full benefit of the potential advantages of ICTs requires the development of special tools and methods which are the focus of the study. We show how to design ICTs considering several topologies and different methods, from the most precise and time-consuming to the less accurate but more quickly calculated. The explanation of the ICT design is divided in four main parts: Copper Losses, Core Losses, Flux Density Saturation and Thermal Aspects. Further attention is given to high frequency copper losses since complex phenomena such as skin and proximity effects highly influence the ICT design. Based on Finite Element Method simulations, smart practices are suggested to reduce high and low frequency copper losses, not only in ICTs but also in inductors and transformers. Simple tables are developed to help transformer designers to identify the best configuration of conductors inside a given core window, depending on the current waveform and frequency, number of turns and geometrical parameters. Optimization routines to reduce the ICT total mass, volume, losses or cost are developed and multidimensional interpolation of pre-simulated values of AC resistance and leakage inductance is used to speed up the optimization routine. Comparison of ICT designs with regard to core and conductor material, number of cells and switching frequency is performed. Comparison with regular inductors is also made in order to verify the benefits of this kind of magnetic component. Multilevel converter control aspects applied to three- hase systems is also investigated in terms of the ICT flux. Zero sequence signals, specific for a PWM strategy and converter/load topology, are created in order to minimize the flux in ICTs and consequently reduce even further the mass and size of these components. Comparison between several PWM methods are performed and experimentally verified
2
Kuruc, Lukáš. "Sledování kvality a optimalizace testování na lince AKD." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242152.
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This diploma thesis deals with issue of quality monitoring and final product testing at the AKD line. Output of this thesis is calculation of testing time optimization by Weibull distribution. In the beginning reader is familiar with AKD device, what quality management is and ways how to test final products in electrotechnical manufacturing. Main goal of this thesis is to describe differences between testing methods and optimize Burn-In testing method.
3
Tervo, O. (Oskari). "Transceiver optimization for energy-efficient multiantenna cellular networks." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526219356.
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Abstract This thesis focuses on the timely problem of energy-efficient transmission for wireless multiantenna cellular systems. The emphasis is on transmit beamforming (BF) and active antenna set optimization to maximize the network-wide energy efficiency (EE) metric, i.e., the number of transmitted bits per energy unit. The fundamental novelty of EE optimization is that it incorporates the transceivers' processing power in addition to the actual transmit power in the BF design. The key features of the thesis are that it focuses on sophisticated power consumption models (PCMs), giving useful insights into the EE of current cellular systems in particular, and provides mathematical tools for EE optimization in future wireless networks generally. The BF problem is first studied in a multiuser multiple-input single-output system by using a PCM scaling with transmit power and the number of active radio frequency (RF) chains. To find the best performance, a globally optimal solution based on a branch-reduce-and-bound (BRB) method is proposed, and two efficient designs based on zero-forcing and successive convex approximation (SCA) are derived for practical applications. Next, joint BF and antenna selection (JBAS) is studied, which can switch off some RF chains for further EE improvements. An optimal BRB method and efficient SCA-based algorithms exploiting continuous relaxation (CR) or sparse BF are proposed to solve the resulting mixed-Boolean nonconvex problem (MBNP). In a multi-cell system, energy-efficient coordinated BF is explored under two optimization targets: 1) the network EE maximization and 2) the weighted sum EEmax (WsumEEmax). A more sophisticated PCM scaling also with the data rate and the associated computational complexity is assumed. The SCA-based methods are derived to solve these problems in a centralized manner, and distributed algorithms relying only on the local channel state information and limited backhaul signaling are then proposed. The WsumEEmax problem is solved using SCA combined with an alternating direction method of multipliers, and iterative closed-form algorithms having easily derivable computational complexity are developed to solve both problems. The work is subsequently extended to a multi-cell multigroup multicasting system, where user groups request multicasting data. For the MBNP, a modeling method to improve the performance of the SCA for solving the CR is proposed, aiming at encouraging the relaxed Boolean variables to converge at the binary values. A second approach based on sparse BF, which introduces no Boolean variables, is also derived. The methods are then modified to solve the EE and sum rate trade-off problem. Finally, the BF design with multiantenna receivers is considered, where the users can receive both unicasting and multicasting data simultaneously. The performances of the developed algorithms are assessed via thorough computer simulations. The results show that the proposed algorithms provide 30-300% EE improvements over various conventional methods in the BF optimization, and that JBAS techniques can offer further gains of more than 100%<br>Tiivistelmä Tämä väitöskirja keskittyy ajankohtaiseen energiatehokkaaseen lähetinsuunnitteluun langattomissa solukkoverkoissa, joissa suorituskykymittarina käytetään energiatehokkuuden (energy efficiency (EE)) maksimointia, eli kuinka monta bittiä pystytään lähettämään yhtä energiayksikköä kohti. Työn painopiste on lähettimien keilanmuodostuksen (beamforming (BF)) ja aktiivisten lähetinantennien optimoinnissa. EE-optimoinnin uutuusarvo on ottaa lähettimien prosessoinnin tehonkulutus huomioon keilanmuodostuksen suunnittelussa, varsinaisen lähetystehon lisäksi. Työ antaa hyvän käsityksen erityisesti tämänhetkisten solukkoverkkojen energiatehokkuudesta, ja luo työkaluja EE-optimointiin tulevaisuuden järjestelmissä. Ensin suunnitellaan keilanmuodostus yksisolumallissa, jossa tehonkulutus kasvaa lähetystehon ja aktiivisten radiotaajuusketjujen lukumäärän mukana. Ongelmaan johdetaan optimaalinen ratkaisu, ja kaksi käytännöllistä menetelmää perustuen nollaanpakotukseen tai peräkkäinen konveksi approksimaatio (successive convex approximation (SCA)) -ideaan. Seuraavaksi keskitytään keilanmuodostuksen ja antenninvalinnan yhteisoptimointiin (joint beamforming and antenna selection (JBAS)), jossa radiotaajuusketjuja voidaan sulkea EE:n parantamiseksi. Tähän ehdotetaan optimaalinen menetelmä ja kaksi käytännöllistä SCA-menetelmää perustuen binääristen ja jatkuvien muuttujien yhteisoptimointiongelman relaksaatioon, tai harvan vektorin optimointiin. Monisoluverkon EE-optimoinnissa käytetään yksityiskohtaisempaa tehonkulutusmallia, joka skaalautuu myös datanopeuden ja prosessoinnin monimutkaisuuden mukaan. Työssä käytetään kahta suorituskyvyn mittaria: 1) koko verkon energiatehokkuuden, ja 2) painotettujen energiatehokkuuksien summien maksimointia (weighted sum EEmax (WsumEEmax)). Ensin johdetaan keskitetyt ratkaisut SCA-ideaa käyttäen. Tämän jälkeen keskitytään hajautettuun optimointiin, joka pystytään toteuttamaan paikallisen kanavatiedon avulla, kun matalanopeuksinen skalaariarvojen jako on käytettävissä tukiasemien välillä. Ensin WsumEEmax-ongelma ratkaistaan yhdistämällä SCA ja kerrointen vaihtelevan suunnan menetelmä, ja lisäksi ehdotetaan iteratiivinen suljetun muodon ratkaisu molempiin ongelmiin, joka mahdollistaa tarkan laskennallisen monimutkaisuuden määrityksen. Lopussa työ laajennetaan monisoluverkkoon, jossa tukiasemat palvelevat käyttäjäryhmiä ryhmälähetyksenä. Keskittymällä JBAS-ongelmaan, ensin ehdotetaan lähestymistapa parantaa SCA-menetelmän suorituskykyä yhteisoptimointiongelman relaksaation ratkaisemisessa. Toinen yksinkertaisempi lähestymistapa perustuu harvan vektorin optimointiin, joka ei vaadi binäärisiä muuttujia. Lisäksi menetelmiä muunnellaan myös energiatehokkuuden ja summadatanopeuden kompromissin optimointiin. Lopussa työ ottaa huomioon vielä moniantennivastaanottimet, joka mahdollistaa sekä täsmälähetyksen että ryhmälähetyksen samanaikaisesti. Menetelmien suorituskykyä arvioidaan laajamittaisilla tietokonesimulaatioilla. Tulokset näyttävät väitöskirjan menetelmien lisäävän energiatehokkuutta 30-300% verrattuna lukuisiin perinteisiin menetelmiin BF-optimoinnissa, ja JBAS-menetelmät antavat vielä yli 100% lisää suorituskykyä
4
Wicaksono, Hendro Verfasser], and Jivka [Akademischer Betreuer] [Ovtcharova. "An Integrated Method for Information and Communication Technology (ICT) Supported Energy Efficiency Evaluation and Optimization in Manufacturing: Knowledge-based Approach and Energy Performance Indicators (EnPI) to Support Evaluation and Optimization of Energy Efficiency / Hendro Wicaksono ; Betreuer: J. Ovtcharova." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1117701913/34.
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Wicaksono, Hendro [Verfasser], and Jivka [Akademischer Betreuer] Ovtcharova. "An Integrated Method for Information and Communication Technology (ICT) Supported Energy Efficiency Evaluation and Optimization in Manufacturing: Knowledge-based Approach and Energy Performance Indicators (EnPI) to Support Evaluation and Optimization of Energy Efficiency / Hendro Wicaksono ; Betreuer: J. Ovtcharova." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1117701913/34.
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Šejna, Tomáš. "Posouzení informačního systému firmy a návrh změn." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2016. http://www.nusl.cz/ntk/nusl-240908.
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Diploma thesis is focused on information system assessment and subsequent proposal for its modification. These changes are partly concerned on company requests, where system implemented is, but on the other hand also of development of processes in the time horizon. These proposals of changes and optimization will be afterwards presented and recommended for realization.
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Lopes, Inês Marques. "Ice cream and nutrition: modeling optimal ice cream formulations." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6779.
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Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia<br>It is becoming more urgent for producers to design new products that follow the consumer’s
trends and expectations, such as, “low fat”, “no sugars” or “low calorie” products, while
maintaining the ice cream features.
The aim of this thesis was to develop a computer aided-tool, based on a mathematical model
that helps to design ice cream recipes. By combining different expertise information, a linear
programming model has been developed with the objective of minimizing the recipes calorie
content. It compiles information about ingredients that are commonly used in ice cream
manufacture and their contribution to nutrient and processing constraints. After setting all
requirement constraints for each specific ice cream, the Excel Solver optimization tool, gives a
solution for the model establishing the ingredients and their quantities to be included in the
recipe. The developed model can be easily updated to account for changes in market demands
or production conditions.
It was created a version of the model for each one of the following ice cream types: water ice,
ice cream, milk ice, dairy ice, sorbet and artisanal recipe.
In order to test the effectiveness of the model, seven innovative recipes, using Portuguese
ingredients with healthy benefits, have been created and tested at DuPont, Denmark.
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Tarr, Matthew Aaron. "Characterization and optimization of sample introduction systems for ICP-AES, ICP-MS, and LC-MS." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/27987.
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Ibn, Khedher Hatem. "Optimization and virtualization techniques adapted to networking." Thesis, Evry, Institut national des télécommunications, 2018. http://www.theses.fr/2018TELE0007/document.
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Dans cette thèse, on présente nos travaux sur la virtualisation dans le contexte de la réplication des serveurs de contenu vidéo. Les travaux couvrent la conception d’une architecture de virtualisation pour laquelle on présente aussi plusieurs algorithmes qui peuvent réduire les couts globaux à long terme et améliorer la performance du système. Le travail est divisé en plusieurs parties : les solutions optimales, les solutions heuristiques pour des raisons de passage à l’échelle, l’orchestration des services, l’optimisation multi-objective, la planification de services dans des réseaux actifs et complexes et l'intégration d'algorithmes dans une plate-forme réelle<br>In this thesis, we designed and implemented a tool which performs optimizations that reduce the number of migrations necessary for a delivery task. We present our work on virtualization in the context of replication of video content servers. The work covers the design of a virtualization architecture for which there are also several algorithms that can reduce overall costs and improve system performance. The thesis is divided into several parts: optimal solutions, greedy (heuristic) solutions for reasons of scalability, orchestration of services, multi-objective optimization, service planning in complex active networks, and integration of algorithms in real platform. This thesis is supported by models, implementations and simulations which provide results that showcase our work, quantify the importance of evaluating optimization techniques and analyze the trade-off between reducing operator cost and enhancing end user satisfaction index
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Villaseñor, Milán Ángela. "Development and optimization of methods for elemental quantitative analysis of catalysts and polymers through laser ablation-ICP techniques." Doctoral thesis, Universidad de Alicante, 2018. http://hdl.handle.net/10045/97855.
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En la presente Tesis Doctoral la técnica de ablación laser acoplada a ICP-OES/MS ha sido empleada para analizar muestras sólidas, como catalizadores usados en el refinado del petróleo y polímeros. Se han llevado a cabo dos tipos de análisis, un análisis global de las muestras que proporciona información general y un análisis localizado que permite obtener información acerca de la distribución espacial de los elementos de interés en las muestras. Las diferentes variables de la técnica ablación láser son estudiadas con el fin de seleccionar aquellas que conducen una señal alta y estable, así como a un menor grado de fraccionamiento. Este estudio se realiza para cada tipo de muestra, ya que los resultados dependen de la matriz estudiada. Además, en esta Tesis doctoral se desarrolla un método de calibración para llevar a cabo un análisis cuantitativo de las muestras sólidas, basado en la deposición de patrones líquidos sobre la muestra sólida. Este método es conocido como “dried droplet calibration approach” (DDCA), y permite cuantificar elementos presentes en muestras sólidas sin necesidad de usar materiales de referencia sólidos. Este nuevo método de calibración compensa el fraccionamiento elemental y los efectos de matriz, proporcionando resultados exactos y preciosos para muestras complejas tales como vidrios, catalizadores y polímeros.
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Yeung, King-ho, and 楊景豪. "An optimization model for a solar hybrid water heating and adsorption ice-making system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29632432.
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Winkler, Sven [Verfasser]. "Endwall Contouring Using Numerical Optimization in Combination with the Ice Formation Method / Sven Winkler." München : Verlag Dr. Hut, 2016. http://d-nb.info/1106593553/34.
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Skrzypczak, Alexandre, Alain Thomas, and Guillaume Duponchel. "Paradigms Optimization for a C-Band COFDM Telemetry with High Bit Efficiency." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579655.
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ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV<br>Systems using single carrier modulations for flight test transmissions perfectly fit noisy and time selective channels. However, the densification of the airport environment now makes the aero channel also frequency selective due to multiple reflections on surrounding buildings, especially while taxiing and taking off. Obviously, this has a direct consequence on hardware resources and user data rates. In such a context, COFDM represents an appealing solution thanks to its inherent robustness to multipath fading channels. But a direct application of an off-the-shelf COFDM standard is not straightforward as these standards are designed for specific channels whose characteristics are quite different from the aero one. That is why we made an experiment at Toulouse-Blagnac airport to jointly sound the channel and qualify a COFDM waveform. This paper then describes the construction of the waveform and the results of the channel sounding. From this, different standard paradigms are compared.
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Wanli, William. "The Church of Jesus Christ of Latter-day Saints in Trollhättan Energy optimization." Thesis, Högskolan i Gävle, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36586.
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The world is experiencing increasing energy usage owing to environmental impacts suchas climate change, Ozone layer depletion, and global warming. Energy usage is primarilycategorized into transport, industrial, residential, and service sectors, with the transportationand industrial sectors taking up a considerable chunk of the energy use; Buildings partlydetermine the use of energy globally.This review presents a critical analysis of energy demand and uses in the building sectorconsidering the energy optimization for The Church of Jesus Christ of Latter-day Saints inTrollhättan, including the local energy requirements. The modelling software IDA-ICE isused to conduct simulations for different scenarios. The IDA-ICE software links the actualbuilding images with the isometric views done on a computer. The energy balance ofbuildings is considered with respect to the three methods for heat transfer, the U-value,ventilation, heating load, and cooling load. The study results show that the building relieson electricity and fuel for its energy supply and that fuel consumption takes the highestshare, 60 %. Retrofit 1 (where the oil and electric boilers are replaced by geothermal heatpump with COP 4 for heating and domestic hot water), Retrofit 2 (which keeps changesfrom Retrofit_1 and where a new AHU with a VAV system replaces the existing twoAHUs), and Retrofit 3 (which keeps changes from Retrofit_2 and only connects the heatingsystem to district heating) are designed as part of the findings to understand the variationsin comfort reference, supplied Energy, used Energy, utilized Energy, auxiliary Energy, andthe Energy of all zones during heating and cooling. The model results indicate that Retrofit2 demonstrates better results than the other two since it has a higher energy-saving capacity.The energy reduction for Retrofit model 1 is about 33.4 %, while Retrofit model 2 has 55%and model 3 has 33%, significantly decreasing the associated costs. The LCC analysisshows payback for the first model 6.73 years with an investment cost of 700 000 SEK, thesecond model has 5.84 with 1 million SEK investment, and the third model has 3.4 yearswith 350 000 SEK.
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Winkler, Sven [Verfasser], and Bernhard [Akademischer Betreuer] Weigand. "Endwall contouring using numerical optimization in combination with the ice formation method / Sven Winkler ; Betreuer: Bernhard Weigand." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1118370198/34.
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Khabirova, Maja. "Graphics workflow optimization when editing standard tasks using modern graphics editing programs." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-162763.
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This work focuses on the description and characteristics of common problems which graphic designers face daily when working for advertising agencies. This work describes tasks and organises them according to the type of graphic being processed and the types of output. In addition, this work describes the ways these common tasks can be completed using modern graphics editing software. It also provides a practical definition of a graphic designer and graphic agency. The aim of this work is to map out the fundamental tasks with raster graphics which graphic designers must perform most frequently during their work and to suggest an optimal workflow. As a result, after collating all of the proposed solutions, a manual should take form. It should help to facilitate early stages of work for students who may hold the position of junior graphic designer within advertising agencies.
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Novaes, Cleber Galvão. "Aplicação de técnicas quimiométricas na otimização de métodos usando a espectrometria de emissão óptica com plasma indutivamente acoplado e espectrometria de absorção atômica com chama visando a análise de amostras ambientais." reponame:Repositório Institucional da UFBA, 2011. http://www.repositorio.ufba.br/ri/handle/ri/10024.
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Previous issue date: 2011<br>CAPES<br>Nesta tese é apresentada a aplicação de técnicas quimiométricas na
otimização de métodos usando a espectrometria de emissão óptica com plasma
indutivamente acoplado (ICP OES) e espectrometria de absorção atômica com
chama (F AAS) visando a análise de amostras ambientais.
No primeiro trabalho, variáveis como potência de radiofrequência, vazão
do gás do plasma, vazão do fluxo de nebulização, vazão do gás auxiliar, vazão da
amostra e concentração de ácido nítrico na amostra foram otimizadas através da
aplicação de planejamento fatorial completo e Box-Behnken. Parâmetros analíticos
como precisão, robustez, sensibilidade e exatidão mostraram-se adequados para
determinação de Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Si,
Sn, Sr, Ti, Tl, V e Zn em amostras de água subterrânea, água de rio, efluente e solo
usando ICP OES. A estratégia de medição e o tempo total de análise também foram
otimizados. O novo método foi implantado na rotina do laboratório da CETREL e
está proporcionando uma enorme redução no consumo do argônio, em torno de 35
%, gerando uma economia de aproximadamente 320 m3 de argônio anuais, além da
redução nos custos associados a outros acessórios do ICP OES.
No segundo trabalho, três variáveis de pré-concentração do chumbo (pH,
concentração do tampão e vazão da amostra) foram otimizadas empregando
planejamento fatorial completo 23. O método é baseado na sorção de Pb(II) em uma
minicoluna recheada com uma resina de Amberlite XAD-4 funcionalizada com 4-(5´-
bromo-2´-tiazolilazo)orcinol (Br-TAO). O método apresentou limite de quantificação
de 1,7 μg L-1, faixa linear de 1,7-200 μg L-1 e fator de enriquecimento de 36, para
25,0 mL de amostra. A exatidão do método foi verificada pela determinação de
chumbo em material de referência certificado de água doce NIST 1643d. O método
foi aplicado na determinação de chumbo em amostras de água coletadas na cidade
de Jequié-BA usando F AAS. Os teores de chumbo variaram de 4,1 a 5,7 μg L-1.
As ferramentas quimiométricas utilizadas nos dois trabalhos foram muito
eficazes na otimização de variáveis importantes e permitiu um estudo descritivo das
variáveis e suas interações. Os dois métodos apresentaram parâmetros analíticos
adequados para determinação de metais e metalóides em amostras ambientais<br>Salvador
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Meunier, Richard. "Optimization of the elaboration of insulating layers for the gate structures and the passivation of MIS-HEMT transistors on GaN." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30150/document.
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Les potentialités du nitrure de gallium (GaN) et notamment de l'hétérostructure AlGaN/GaN, semiconducteur à large bande interdite, en font un matériau particulièrement intéressant en électronique de puissance, notamment pour des applications haute tension, haute température et haute fréquence. L'objectif de ce travail de thèse était de développer et d'optimiser l'étape d'isolation de la grille lors la réalisation de transistors MIS-HEMT de puissance sur hétérostructure AlGaN/GaN, le but étant de réduire les courants de fuite de grille sans perturber les propriétés du transistor. Après avoir évaluation, le choix s'est porté sur l'alumine Al2O3 déposé par ALD comme diélectrique de grille. L'étude s'est d'abord concentrée sur l'analyse de l'influence de traitements, chimiques ou plasma, sur la contamination de la surface d'AlGaN au travers d'analyses XPS et AFM. Puis, l'influence du diélectrique de grille a été évalué à travers la réalisation et la mesure électrique de dispositifs, diodes et transistors, en variant les méthodes de dépôt par ALD. Enfin, l'impact d'un recess par gravure ICP-RIE partielle ou complètes de la barrière d'AlGaN sous la grille a été étudiée. La réalisation d'un HEMT passe par l'étape critique du dépôt du diélectrique de grille sur le semiconducteur, et le contrôle de la qualité de l'interface " diélectrique/AlGaN " est donc une étape fondamentale car elle influe sur les propriétés électriques du composant. Ce contrôle comprend le traitement de surface du semiconducteur, mais aussi la nature et la technique de dépôt du diélectrique. Ainsi il apparaît à travers l'étude qu'un traitement de surface à l'ammoniaque à haute température est le plus efficaces pour retirer les contamination en oxydes natifs. Les mesures électriques, C(V) et Id(Vg), ont quant à elle montrés la supériorité de la PEALD par rapport à un dépôt thermique conventionnel. Ceci peut s'expliquer par le fait que le plasma oxygène qui entre jeu lors du dépôt de l'alumine par PEALD semble nettoyer la surface lors des premiers cycles, retirant notamment la contamination carbone. Cela permet d'avoir une meilleure interface entre l'alumine et le semi-conducteur, limitant les pièges à l'interface et dans l'oxyde. Cela a réduit de manière considérable les courants de fuite de grille, sans détériorer la qualité et la rapidité de la transition entre l'état on et off. De plus, les HEMTs réalisé étant de type normally-off, le recess de grille par gravure ICP-RIE a été implémenté afin de rendre moins négative la tension de pincement. Cela a été réalisé avec succès, notamment avec la réalisation d'un composant de type noramlly-off grâce à un recess total de la barrière d'AlGaN sous la grille. Des résultats à l'état de l'art ont été obtenus à travers une approche simple, et un processus de création de transistors robuste et hautement reproductible, avec une réduction importante des courants de fuite de grille et une pente sous le seuil record. Afin de compléter l'étude il conviendra par la suite de réaliser des études de fiabilité, notamment à travers des mesures dynamiques pour évaluer notamment les phénomènes de dégradation du Ron<br>With its large band gap, Gallium Nitride (GaN) semiconductor is one of the most promising materials for new power devices generation thanks to its outstanding material properties for high voltage, temperature and frequency applications. The main objective of this thesis was the development and optimization of the insulating step taking place in the elaboration of MIS-HEMT transistors on an AlGaN/GaN heterstroctructure. In order to reduce gate leakage currents without degrading the device properties, alumina Al2O3 deposited by ALD was chosen as a gate dielectric. The study was first centered on the influence of surface treatments, chemical or plasma, regarding surface contamination. Their impact was analyzed through XPS and AFM. Secondly, electrical measures were performed on complete MIS-HEMT diodes and transistors to evaluate the influence of the alumina insulating layer depending on the ALD deposition method. Lastly, partial and full recess of the AlGaN barrier was studied via ICP-RIE etching. The gate dielectric deposition is one of the crucial steps intervening in the HEMT creation process. The quality and control at the Al2O2/AlGaN interface being paramount, it will directly influence the device's electric properties. This involves control ing the semiconductor surface, but also the nature and deposition technique of the dielectric. As such, an ammonia-based treatment at high temperature appears to be the most efficient in reducing native oxygen contamination. Regarding electric performances, C(V) and Id(Vg) measures showed the superiority of PEALD compared to traditional thermal ALD deposition. This can be explained by the fact that the oxygen plasma used as oxydant during the alumina deposition by PEALD seems to clean the surface during the first cycles, mostly by reducing carbon contamination. This allowed to achieve a better interface between the semiconductor and the insulting layer, thus limiting traps at the interface or in the oxyde. This allows to considerably reduce gate leakage currents, without degrading the quality and transition sharpness between the on and off state. Moreover, the realized HEMTs being normally-off, gate recess etching via ICP-RIE was implemented in order to make the threshold voltage less negative. This was successfully achieved, especially through the realization of a normally-off transistors thanks to a full recess of the AlGaN barrier under the gate. State of the art results were achieved through a simple approach, and a robust and highly reproducible transistor elaboration process, with great reduction of gate leakage currents and a record sub-threshold slope. In order to complete the study, it will be necessary in the future to proceed to viability studies, especially through dynamic electric evaluation, in order to evaluate for instance Ron degradation phenomenons
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Wu, Debo [Verfasser], Thomas [Akademischer Betreuer] Pichler, and Andrea [Akademischer Betreuer] Koschinsky. "Optimization of methodology for the simultaneous speciation of inorganic As, Sb and Se in fluid samples by sector-field ICP-MS coupled to HPLC / Debo Wu. Gutachter: Thomas Pichler ; Andrea Koschinsky. Betreuer: Thomas Pichler." Bremen : Staats- und Universitätsbibliothek Bremen, 2015. http://d-nb.info/1075609313/34.
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Cervantes, Rivera Hans Macálisther, and Minchola Gonzalo Octavio Chicle. "Propuesta de mejora de productividad basado en un Sistema Básico de Gestión por Procesos en las Mypes productoras de granada en el distrito de Santiago en Ica." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/654474.
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El presente proyecto está enfocado en analizar el proceso de producción de la granada. Todas las actividades físicas, que intervienen dentro del proceso productivo, determinarán los niveles de producción que se originan en cada campaña. Estas cualidades presentan una gran importancia para elevar el valor del producto dentro de los distintos mercados de exportación, como Holanda, Francia, Ucrania; a los que apuntan los productores de Santiago-Ica.
Se ha identificado que el sector agrícola representa la mayor proporción dentro de los ingresos económicos que percibe el país en temas de exportación. Dentro de este mismo sector, se ha percibido que la Granada ha experimentado un constante crecimiento en sus niveles de exportación debido a que la demanda de esta fruta se ha incrementado considerablemente en países europeos y asiáticos. La presente investigación se enfoca a satisfacer las grandes demandas de otros países, incrementando las capacidades de producción en las MYPES.
Se han realizado evaluaciones del proceso de producción actual que se ejecutan en esta zona geográfica tomando como referencia las buenas prácticas agrícolas que son usadas en otros países con mejores indicadores de productividad. Este análisis ha permitido obtener diferencias significativas entre ambos procesos; es por ello que se ha elaborado un modelo propuesto, que será implementado usando herramientas básicas de la gestión por procesos para estandarizar las actividades a realizar y obtener resultados mejor estructurados que estén alineados a incrementar los niveles de producción y la optimización en el uso de los recursos.
Los resultados obtenidos serán analizados y usados para la generación de indicadores, las cuales han sido seleccionadas con la técnica SMART, que nos permitan comparar la productividad obtenida de un mismo pedazo de terreno antes y después de la propuesta de mejora.
Finalmente, el modelo propuesto será consultado y validado usando la técnica de juicio de expertos para lo cual consultamos con usuarios de las MYPES del sector y con expertos en el manejo de herramientas de gestión por procesos. Estos resultados serán analizados usando la matriz PUGH como herramienta para cuantificar la aprobación de cada uno de los expertos.<br>This project is focused on analyzing the pomegranate production process. All the physical activities that intervene in the production process will determine the levels of production that originate in each campaign. These qualities are of great importance to raise the value of the product within the different export markets, such as Holland, France, Ukraine; to which the producers of Santiago-Ica are targeting.
It has been identified that the agricultural sector represents the largest proportion within the economic income that the country receives in export issues. Within this same sector, it has been perceived that Granada has experienced a constant growth in its export levels due to the fact that its demand has increased considerably in European and Asian countries. This research is focused on satisfying the great demands of other countries, increasing the production capacities in SMEs.
Evaluations of the current production process that are carried out in this geographical area have been carried out, taking as a reference the good agricultural practices that are used in other countries with better productivity indicators. This analysis has allowed to obtain significant differences between both processes; That is why a proposed model has been developed, which will be implemented using basic tools of process management to standardize the activities to be carried out and obtain better structured results that are aligned to increasing production levels and optimizing the use of means.
The results obtained will be analyzed and used to generate indicators, which have been selected with the SMART technique, which allow us to compare the productivity obtained from the same piece of land before and after the improvement proposal.
Finally, the proposed model will be consulted and validated using the expert judgment technique, for which we consult with users of SMEs in the sector and with experts in the management of process management tools. These results will be analyzed using the Pugh matrix as a tool to quantify the approval of each of the experts.<br>Tesis
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Santos, Juracir Silva. "Estratégias analíticas para determinação de urânio em amostras de águas e efluentes industriais." reponame:Repositório Institucional da UFBA, 2013. http://www.repositorio.ufba.br/ri/handle/ri/9809.
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Tese - Juracir Silva Santos.pdf: 2944425 bytes, checksum: 25ce15e90c56cd72422b47a715f94a0f (MD5)<br>CAPES<br>O trabalho foi desenvolvido no âmbito do projeto 993/2007 – “Desenvolvimento de estratégias analíticas para a determinação de urânio em amostras ambientais e industriais – Monitoramento ambiental da cidade de Caetité, Bahia” e viabilizado através de uma parceria firmada entre a Universidade Federal da Bahia e a Comissão Nacional de Energia Nuclear. Neste trabalho foram desenvolvidas estratégias para a determinação de urânio em amostras de águas naturais e efluentes provenientes de mina de urânio. Uma avaliação crítica da determinação de urânio por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) foi realizada usando planejamentos fatoriais e Doehlert envolvendo as variáveis: concentração de ácido, potência de radiofrequência e vazão do gás de nebulização. Simultaneamente, cinco linhas de emissão foram estudadas (367,007; 385,464; 385,957; 386,592 e 409,013 nm), na presença de HNO3, H3C2OOH ou HCl. As determinações empregando o HNO3 foram as mais sensíveis. Entre as variáveis estudadas, a vazão do gás de nebulização foi a mais significativa, para as cinco linhas de emissão. A presença de cálcio causou interferência na intensidade de emissão de algumas linhas e ferro não interferiu (pelo menos até 10 mg L−1) nas cinco linhas estudadas. A presença de outros 13 elementos foi avaliada simultaneamente e, não afetou a intensidade de emissão. Sob condições otimizadas, usando a linha 385,957 nm, o método permite a determinação de urânio com limite de quantificação de 30 μg L−1 e precisão, expressa como RSD, menor que 2,2% para as concentrações de urânio de 500 e 1000 μg L−1. Na segunda estratégia, um procedimento em fluxo, com alta sensibilidade foi proposto para a determinação de urânio em amostras de água. Uma cela de caminho óptico de 100 cm baseada em guia de onda com núcleo líquido (LCW) foi usada para aumentar a sensibilidade do método do arsenazo III e possibilitar a detecção de urânio para atender aos limites estabelecidos pela legislação ambiental vigente. O sistema de fluxo foi desenvolvido com microbombas solenoide, a fim de melhorar a mistura e minimizar o consumo de reagente, bem como a geração de resíduos. A resposta linear do método observada foi 5,0-150,0 µg L-1, com limite de detecção, RSD e frequência de amostragem estimados em 1,3 µg L-1 (99,7% de confiança), 0,7% (n = 20) e 40 determinações por hora, respectivamente. O consumo de arsenazo III foi reduzido em 1250 vezes em comparação com um procedimento de pré-concentração em fase sólida. A exatidão dos métodos foi confirmada pela análise de dois materiais de referência de laboratório fornecido pela CNEN. Além disso, uma amostra de efluente foi analisada por espectrometria de massas com plasma indutivamente acoplado (ICP-MS) e as recuperações foram satisfatórias. Os métodos desenvolvidos foram aplicados na determinação de urânio em água potável, de rio e de poço, e efluentes industriais provenientes das minas de extração de urânio da cidade de Caetité. Os resultados encontrados para urânio em amostras de água potável de Caetité estavam abaixo do limite de quantificação dos métodos, exceto para uma amostra de água de poço subterrâneo (17,0 ± 0,8 µg L-1) e uma amostra de água de rio coletada nas imediações da mina (9,6 ± 0,8 µg L-1).<br>Salvador
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Lapioli, Simone. "Energy retrofit of an office building in Stockholm: feasibility analysis of an EWIS." Thesis, KTH, Installations- och energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190992.
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The energy retrofit of existing buildings has always been a challenging task to accomplish. The example of the Swecohuset building, proves how an integrated approach design between architectural and energetic aspects as well as the use of well-known and efficient technologies are key aspects to achieve the energy-saving goal. This work, in the first part describes the Swecohuset retrofit process, along with the reasons behind the choices which have led to the current result of a reduction by 2/3 of the energy need for space conditioning purposes. Then, in the second part, after a brief focus on the passive aspects which characterize the current energy performance of the building, it is carried out a feasibility analysis of an EWIS (external wall insulation system) by studying its interaction with a complex system as an optimization problem, with the main purpose of understanding the basis of the BPO and explore further building potentialities.<br>SIRen
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Hayati, Abolfazl. "Natural Ventilation and Air Infiltration in Large Single‑Zone Buildings : Measurements and Modelling with Reference to Historical Churches." Doctoral thesis, Högskolan i Gävle, Energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24612.
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Natural ventilation is the dominating ventilation process in ancient buildings like churches, and also in most domestic buildings in Sweden and in the rest of the world. These buildings are naturally ventilated via air infiltration and airing. Air infiltration is the airflow through adventitious leakages in the building envelope, while airing is the intentional air exchange through large openings like windows and doors. Airing can in turn be performed either as single-sided (one opening) or as cross flow ventilation (two or more openings located on different walls). The total air exchange affects heating energy and indoor air quality. In churches, deposition of airborne particles causes gradual soiling of indoor surfaces, including paintings and other pieces of art. Significant amounts of particles are emitted from visitors and from candles, incense, etc. Temporary airing is likely to reduce this problem, and it can also be used to adjust the indoor temperature. The present study investigates mechanisms and prediction models regarding air infiltration and open-door airing by means of field measurements, experiments in wind tunnel and computer modelling. In natural ventilation, both air infiltration and airing share the same driving forces, i.e. wind and buoyancy (indoor-outdoor temperature differences). Both forces turn out to be difficult to predict, especially wind induced flows and the combination of buoyancy and wind. In the first part of the present study, two of the most established models for predicting air infiltration rate in buildings were evaluated against measurements in three historical stone churches in Sweden. A correction factor of 0.8 is introduced to adjust one of the studied models (which yielded better predictions) for fitting the large single zones like churches. Based on field investigation and IR-thermography inspections, a detailed numerical model was developed for prediction of air infiltration, where input data included assessed level of the neutral pressure level (NPL). The model functionality was validated against measurements in one of the case studies, indicating reasonable prediction capability. It is suggested that this model is further developed by including a more systematic calibration system for more building types and with different weather conditions. Regarding airing, both single-sided and cross flow rates through the porches of various church buildings were measured with tracer gas method, as well as through direct measurements of the air velocity in a porch opening. Measurement results were compared with predictions attained from four previously developed models for single‑sided ventilation. Models that include terms for wind turbulence were found to yield somewhat better predictions. According to the performed measurements, the magnitude of one hour single-sided open-door airing in a church typically yields around 50% air exchange, indicating that this is a workable ventilation method, also for such large building volumes. A practical kind of diagram to facilitate estimation of suitable airing period is presented. The ability of the IDA Indoor Climate and Energy (IDA-ICE) computer program to predict airing rates was examined by comparing with field measurements in a church. The programs’ predictions of single-sided airflows through an open door of the church were of the same magnitude as the measured ones; however, the effect of wind direction was not well captured by the program, indicating a development potential. Finally, wind driven air flows through porch type openings of a church model were studied in a wind tunnel, where the airing rates were measured by tracer gas. At single-sided airing, a higher flow rate was observed at higher wind turbulence and when the opening was on the windward side of the building, in agreement with field measurements. Further, the airing rate was on the order of 15 times higher at cross flow than at single-sided airing. Realization of cross flow thus seems highly recommendable for enhanced airing. Calibration constants for a simple equation for wind driven flow through porches are presented. The measurements also indicate that advection through turbulence is a more important airing mechanism than pumping. The present work adds knowledge particularly to the issues of air infiltration and airing through doors, in large single zones. The results can be applicable also to other kinds of large single-zone buildings, like industry halls, atriums and sports halls.<br>Naturlig ventilation är den dominerande ventilationsprocessen i äldre byggnader såsom kyrkor, och även i de flesta småhus i Sverige och övriga delar av världen. Luftinfiltration och vädring utgör viktiga komponenter i naturlig ventilation, där luftinfiltration är luftflöde genom oavsiktliga läckage i byggnadsskalet, medan vädring är avsiktligt luftutbyte genom stora öppningar såsom fönster och dörrar/portar. Vädring kan i sin tur ske ensidigt (genom en öppning) eller som tvärdrag (genom två eller flera öppningar belägna på olika ytterväggar). Det totala luftutbytet påverkar värmeförluster och inomhusluftens kvalité. I kyrkor orsakar avsättning av luftpartiklar en gradvis nedsmutsning av invändiga ytor, inklusive väggmålningar och andra konstföremål. Betydande mängder partiklar avges från besökare, tända ljus, rökelse, o.d. Tillfällig vädring kan minska detta problem, men även användas för att justera innetemperaturen. Föreliggande studie analyserar mekanismer och predikteringsmodeller gällande luftinfiltration och dörrvädring genom fältmätningar, vindtunnelförsök och datorsimuleringar. Luftinfiltration och vädring har samma drivkrafter, d.v.s. vind och termik (inne‑ute temperaturskillnader). Båda dessa drivkrafter är svåra att predicera, särskilt vindinducerade flöden och kombinationen av termik och vind. Två av de mest etablerade modellerna för luftinfiltrationsprediktering i byggnader har utvärderats via mätningar i tre kulturhistoriska stenkyrkor i Sverige. En korrigeringsfaktor av 0,8 föreslås för bättre prediktion av den ena modellen (som gav bäst resultat) gällande höga en-zonsbyggnader såsom kyrkor. En detaljerad numerisk modell är utvecklad för luftinfiltrationsprediktering, där indata baseras på fältundersökningar, inkl. IR-termografering och uppmätt av neutrala tryckplanet (NPL). Modellens funktionalitet har validerats via mätningar i en av fallstudierna och pekar på tämligen god prediktionsprestanda. Vidare utveckling av modellen föreslås, inkl. ett mer systematiskt kalibreringssystem, för olika typer av byggnader och väderförhållanden. Gällande vädring mättes både ensidigt flöde och tvärdrag genom portar i olika kyrkobyggnader med hjälp av spårgas samt direkta lufthastighetsmätningar i portöppning. Mätresultaten jämfördes med erhållna prediktioner från fyra tidigare utvecklade modeller för ensidig ventilation. De modeller som tog hänsyn till vindturbulens gav något bättre resultat. Enligt utförda mätningar medför en timmes ensidig portvädring i en kyrka cirka 50 % luftutbyte, vilket indikerar att detta är en tillämpbar ventilationsmetod, även för så pass stora byggnadsvolymer. Ett särskilt vädringsdiagram presenteras, som syftar till att underlätta uppskattning av erforderlig vädringsperiod. Vidare studerades predikteringsprestanda hos IDA Indoor Climate and Energy (IDA-ICE) simuleringsprogram avseende vädring, där simuleringsdata jämfördes med fältmätningar i en kyrka. Programmets prediktion av ensidigt luftflöde genom en öppen kyrkport var av samma storlekordning som det uppmäta; dock klarade programmet inte av att hantera inverkan av vindriktning så väl, vilket pekar på en utvecklingspotential. Avslutningsvis undersöktes vinddrivet flöde igenom portöppningar i en kyrkmodell i vindtunnel, där luftomsättningen mättes med hjälp av spårgasmetoden. Vid ensidig vädring observerades högre flöde vid högre vindturbulens och när öppningen var på vindsidan av byggnaden, i överensstämmelse med fältmätningarna. Dessutom var vädringsflödet vid tvärdrag i storleksordningen 15 högre än det vid ensidig vädring. Det verkar alltså som att man kan öka vädringstakten avsevärt om man kan åstadkomma tvärdrag. Kalibreringskonstanter presenteras också för en enkel ekvation för vinddrivet flöde genom portar. Vindtunnelstudien indikerar vidare att advektion genom turbulens är en viktigare vädringsmekanism än pumpning. Föreliggande arbete bidrar med kunskap speciellt kring luftinfiltration och vädring genom portar i höga en-zonsbyggnader. Resultaten kan även vara tillämpliga på andra typer av höga en-zonsbyggnader såsom industrihallar, atrier/ljusgårdar och idrottshallar.<br>Church project
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Sanchez, Gaëtan. "L'électrophysiologie temps-réel en neuroscience cognitive : vers des paradigmes adaptatifs pour l'étude de l'apprentissage et de la prise de décision perceptive chez l'homme." Phd thesis, Université Claude Bernard - Lyon I, 2014. http://tel.archives-ouvertes.fr/tel-01058541.
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Aujourd'hui, les modèles computationnels de l'apprentissage et de la prise de décision chez l'homme se sont raffinés et complexifiés pour prendre la forme de modèles génératifs des données psychophysiologiques de plus en plus réalistes d'un point de vue neurobiologique et biophysique. Dans le même temps, le nouveau champ de recherche des interfaces cerveau-machine (ICM) s'est développé de manière exponentielle. L'objectif principal de cette thèse était d'explorer comment le paradigme de l'électrophysiologie temps-réel peut contribuer à élucider les processus d'apprentissage et de prise de décision perceptive chez l'homme. Au niveau expérimental, j'ai étudié les décisions perceptives somatosensorielles grâce à des tâches de discrimination de fréquence tactile. En particulier, j'ai montré comment un contexte sensoriel implicite peut influencer nos décisions. Grâce à la magnétoencéphalographie (MEG), j'ai pu étudier les mécanismes neuronaux qui sous-tendent cette adaptation perceptive. L'ensemble de ces résultats renforce l'hypothèse de la construction implicite d'un a priori ou d'une référence interne au cours de l'expérience. Aux niveaux théoriques et méthodologiques, j'ai proposé une vue générique de la façon dont l'électrophysiologie temps-réel pourrait être utilisée pour optimiser les tests d'hypothèses, en adaptant le dessin expérimental en ligne. J'ai pu fournir une première validation de cette démarche adaptative pour maximiser l'efficacité du dessin expérimental au niveau individuel. Ce travail révèle des perspectives en neurosciences fondamentales et cliniques ainsi que pour les ICM
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Bonan, Bertrand. "Assimilation de données pour l'initialisation et l'estimation de paramètres d'un modèle d'évolution de calotte polaire." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00930097.
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L'évolution des calottes polaires est régie à la fois par une dynamique d'écoulement complexe et par des mécanismes tel le glissement à la base, la température de la glace ou le bilan de masse en surface. De plus, de nombreuses boucles de rétroactions sont constatées entre les différents phénomènes impliquées. Tout ceci rend la modélisation de cette évolution complexe. Malgré tout, un certain nombre de modèles ont été développés dans cette optique. Ceux-ci font tous intervenir des paramètres influents qui dans certains cas sont peu ou pas connus. Ils nécessitent donc d'être correctement spécifiés. L'assimilation de données peut permettre une meilleure estimation de ces paramètres grâce à l'utilisation d'observations qui sont peu nombreuses en glaciologie. Dans cette thèse, nous nous intéressons à la mise en place de systèmes d'assimilation performants pour deux problèmes inverses concernant l'évolution des calottes polaires. Pour mieux nous concentrer sur ce point, nous avons travaillé avec un modèle d'évolution de calotte simplifié (appelé Winnie) qui, cependant, représente bien la plupart des processus complexes de la dynamique de la glace, et permet de travailler à différentes échelles de temps. Dans un premier temps, nous mettons en place une approche 4D-Var pour la reconstruction de l'évolution d'un paramètre climatique influant sur l'évolution d'une calotte sur une échelle de temps typique de 20 000 ans. Elle nécessite notamment l'écriture du code adjoint du modèle. Dans un second temps, nous nous intéressons au problème du spin-up. Ce problème de calibration du modèle pour des simulations à échelle de temps courtes (pas plus de 100 ans) consiste plus particulièrement en la reconstruction conjointe de l'état initial, de la topographie du socle rocheux et des paramètres de glissement basal. Nous développons ici une approche filtre de Kalman d'ensemble pour résoudre ce problème.
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Cougo, Bernardo. "Design and Optimization of InterCell Transformers for Parallel MultiCell Converters." Phd thesis, 2010. http://oatao.univ-toulouse.fr/7037/1/cougo.pdf.
Full textAbstract:
In recent years, the interest for parallel multicell converters has grown, which is partially due to the possibility of coupling the inductors used to connect the different commutation cells together. Coupling the inductors to form an InterCell Transformer (ICT) does not usually modify the output current, but it reduces the current ripple in the windings and the flux swing in some regions of the core. It can be shown that this brings a reduction of copper and core losses in the magnetic component. The reduction of the phase current ripple also reduces the difference between turn on and turn off current in the switches, which brings a reduction of switching losses for devices generating more losses at turn off than at turn on. The design of an ICT is not that different from any other magnetic component but it is very specific and inherent features must be taken into account. Taking full benefit of the potential advantages of ICTs requires the development of special tools and methods which are the focus of the study. We show how to design ICTs considering several topologies and different methods, from the most precise and time-consuming to the less accurate but more quickly calculated. The explanation of the ICT design is divided in four main parts: Copper Losses, Core Losses, Flux Density Saturation and Thermal Aspects. Further attention is given to high frequency copper losses since complex phenomena such as skin and proximity effects highly influence the ICT design. Based on Finite Element Method simulations, smart practices are suggested to reduce high and low frequency copper losses, not only in ICTs but also in inductors and transformers. Simple tables are developed to help transformer designers to identify the best configuration of conductors inside a given core window, depending on the current waveform and frequency, number of turns and geometrical parameters. Optimization routines to reduce the ICT total mass, volume, losses or cost are developed and multidimensional interpolation of pre-simulated values of AC resistance and leakage inductance is used to speed up the optimization routine. Comparison of ICT designs with regard to core and conductor material, number of cells and switching frequency is performed. Comparison with regular inductors is also made in order to verify the benefits of this kind of magnetic component. Multilevel converter control aspects applied to three- hase systems is also investigated in terms of the ICT flux. Zero sequence signals, specific for a PWM strategy and converter/load topology, are created in order to minimize the flux in ICTs and consequently reduce even further the mass and size of these components. Comparison between several PWM methods are performed and experimentally verified.
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Hung, Sheng-Chin, and 洪聖欽. "Novel Multi-level Clock Driving Technique and Circuit-Simulation-Based Multi-objective Evolutionary Algorithm for Design Optimization of a-Si:H TFTs Gate Driver Circuits for Bio-ICT Panel Display Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/64571214014222339379.
Full textAbstract:
碩士<br>國立交通大學<br>生醫工程研究所<br>104<br>In Information and Communication Technology (ICT), the panel display had been widely used in many applications, such as TVs, cell phones, flats, multi-parameter monitors, and ultrasound medical equipments. The structure of TFT-LCD has a backlight unit and a panel display is composed of the active matrix which has gate lines controlled by ASG driver circuits, liquid crystal (LC), the transparent electrode and the color filter (CF) film between two polarizer films. Nowadays, panel displays with various sizes are widely used. To fabricate panel displays with high performance and competitiveness, ASG driver circuits play one of key techniques. In general, ASG driver circuit designs strongly rely on adjusting and testing by experienced engineers. However, with the diverse needs for panel displays of information, communication, and biomedical science, designs of ASG driver circuits are getting more and more complex. Thus, we should consider more engineering parameters which need to be optimized at the same time. The genetic algorithm (GA) is usually used for circuit designs, which we can only write one cost function with many design specifications. However, due to many characteristics of ASG driver circuits, the adjusting of the cost function is very difficult. Recently, the multi-objective evolutionary algorithm (MOEA) which can optimize many cost functions at the same time has become more popular in circuit designs.
In this study, we optimize the ASG driver circuits by using the MOEA. To improve the power consumption of panel display, we propose the multi-level clock driving method. Cooperating with display manufacturer in Taiwan, we successfully fabricate the sample of the optimized ASG driver circuit which has excellent characteristics. First, the problem of the ASG driver circuit on unified optimization framework can be seperated into two parts, the circuit problem and the solver. The configuration file of the circuit problem calls the mask file which provides the positions of masked parameters as well as the parameter file which sets the ranges of parameters. The configuration file also provides parameters to intermediate _file (written by C++ program) for optimization. The solver generates and chooses the solutions. Furthermore, it also calls the external circuit simulator to calculate the characteristics of ASG driver circuits. The terminal condition is according to generations setting by the configuration file.
We design a six-stage ASG driver circuit by using optimized method based on the MOEA. Each stage of this ASG driver circuit has 17 a-Si:H TFTs and 4 capacitors. The objective specifications are the fall time < 3 s and the peak voltage of the ripple < -9 V. The fall time and the peak voltage of the ripple derived from the original design are 4.78 s and -8.81 V, respectively. After optimization, the fall time successfully decrease to 2.65 s, and the peak voltage of the ripple decrease to -9.07 V. Then, in order to reduce the power consumption, we add a novel 3-level clock driving to the optimized ASG driver circuit. The fall time further reduce to 2.35 _s and the peak voltage of the ripple reduce to -9.96 V. Overall, the fall time has about 50 % reduction. Moreover, the fall time of measured data is 2.48 s; the peak voltage of the ripple is -11.3 V. The measured data has a good agreement with the values of simulations, and the ripple of ASG driver circuit also become more smoother.
In addition, stress effect would affect the stability and the lifetime of products. The factors of stress effect are temperature, the magnitude of bias voltages and the conducting time. Because of high level voltages, each TFT will suffer from the offset of the threshold voltage. Therefore, we hope the conducting time of TFT become shorter. In Chapter 4, we drive the ASG driver circuit by using three clock signals, and its duty ratio is 33%; in Chapter 5, we design a twelve-stage ASG driver circuit with four clock signals by using optimized method based on the MOEA, and successfully reduce the duty ratio to 25% which decreasing the stress effect. Each stage of the ASG driver circuit has 13 a-Si:H TFTs and 2 capacitors. The objective speci_cations are the rise time < 3.5 s, the fall time < 5.5 s, the amplitude of the ripple < 1.2 V, the total width of TFTs < 12000 m and the clock Ctotal < 25 pf. After optimization, the rise time successfully decrease from 3.63 s to 3.29 s (9% reduction), the fall time decrease from 5.96 s to 5.37 s (10% reduction), the amplitude of the ripple decrease from 1.23 V to 1.15 V (7% reduction), the total width of TFTs decrease from 13550 m to 11635 m (14% reduction), and the clock Ctotal decrease from 25.8 pf to 21.87 pf (15% reduction).
In this thesis, Chapter 1 introduces the background, the applications of panel displays, and literature reviews. The process of a-Si:H TFT, the parameter extractor, and operations of the basic ASG driver circuit are shown in Chapter 2. Chapter 3 illustrates the multi-objective evolutionary algorithm as well as the unified optimization framework and give an example to explain the programs and file formation. In Chapter 4, we use the optimized method based on the MOEA to design a six-stage ASG driver circuit. Each stage of the ASG driver circuit has 17 a-Si:H TFTs and 4 capacitors. After that, we apply a novel multi-level clock driving to the optimized ASG driver circuit and fabricate the sample to be measured. In Chapter 5, we further design a twelve-stage ASG driver circuit by using the optimized method based on the MOEA. Each stage of the ASG driver circuit has 13 a-Si:H TFTs and 2 capacitors, and the sample of this ASG driver circuit is fabricating. Chapter 6 will conclude this study and give the future works.
Overall, in this thesis, we have successfully designed a six-stage ASG driver circuit by using optimized method based on the MOEA. To improve the power consumption of panel display and characteristics of the ASG driver circuit, we have proposed the 3-level clock driving method. The fall time has about 50% reduction, and it can increase the contrast ratio of panel displays. Ripple become more smoother, and it can increase the stability of panel displays. The most important is we have fabricated the sample of optimized ASG driver circuit with the display manufacturer in Taiwan and the measured data also has a good agreement and feasibility with our researches. Moreover, we added more objectives, and designed a twelve-stage ASG driver circuit by using optimized method based on the MOEA. We have successfully improved all characteristics of the ASG driver circuit at the same time, such as amplitude of the fall time, the total width of TFTs and the clock Ctotal have over 10% reduction, the ripple has 7% reduction and the rise time also has 9% reduction. This study can apply to medium or large panel products with high performance and competitiveness. With the increasing of specification requirements, ASG driver circuit designs are getting more and more complex. Innovation of the optimized method based on the MOEA in this study can be continuously discussed in the future. The designed of the novel clock drivings is also one of key techniques to improve characteristics of ASG driver circuits.
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Feller, Shani. "Investigating ICA for EEG electrode optimization for a sensorimotor BCI." Thesis, 2020. https://hdl.handle.net/10539/31108.
Full textAbstract:
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2020<br>A robotic/orthotic hand that is controlled by an electroencephalograph (EEG)-based brain computer interface (BCI) which can perform wrist extension (WE) and wrist flexion (WF), can benefit motor impaired individuals to perform everyday activities. Numerous EEG electrodes are typically needed for the spatial resolution required for this task. However, this makes the system expensive, time-consuming to set up and uncomfortable for the user. This research explores the development of a new electrode reduction method that produces an optimised and reduced EEG electrode set, when differentiating between WE and WF movements. A 128-electrode, EEG database consisting of recordings from 5 subjects was used in this study. The method utilises independent component analysis (ICA) and features related to event-related desynchronization and resynchronization (ERD/ERS) modulations, to produce a reduced electrode set. The method was applied to two movement type investigations: 1) right-hand and left-hand movements and 2) unilateral WE and WE movements. The effectiveness of the method was tested by evaluating the amount of motor-control information that was retained during the electrode reduction. This was done by combining the analysis of three tests: 1) classification accuracy. 2) visual comparison of the inter-trial variance plots of ERD/ERS. 3) comparing the amount of variance retained across all electrodes sets. The results suggest that the optimal channel configuration for both investigations was a 16-electrode configuration. The 16-electrode configuration obtained a classification accuracy of 70.51 % and 61.61 % for investigation 1 and investigation 2 respectively which is a loss of classification accuracy of 12.01% and 11.16 % respectively, when compared to using the full electrode set. This research illustrates the potential in using ICA as a primary technique for electrode reduction and suggests that non-motor related electrodes may have an important role in recording motor-related cortical activity<br>CK2021
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Yang, Bing-Shiang, and 楊秉祥. "The Simulation and Optimization of Ice-Storage Air-Conditioning System." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/68527726880873619341.
Full textAbstract:
碩士<br>國立臺灣大學<br>機械工程學研究所<br>84<br>The first phase of Ca2+ mobilization is a peak transient phase of Ca2+ release from intracellular Ca2+ pools, and the second phase is a long sustained phase, due to net extracellular Ca2+ influx. The mechanisms of Ca2+ influx have been proposed to be directly regulated by receptors, G proteins, second messengers, or other.
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Yu, Shih-An, and 于斯安. "Power Optimization in 3D ICs Considering Process Variations and Thermal Effect." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/05631024634348814324.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系所<br>96<br>The three-dimensional integrated circuits (3D ICs) have been viewed as an effective methodology to overcome the bottleneck caused by the long interconnects in the 2D IC. However, the higher temperature becomes a big challenge for 3D ICs. On-chip temperature can significantly affect the circuit performance so it is necessary to reduce the power dissipation in the circuit. Meanwhile, the process variations, which have a serious influence on the circuit design, are another important issue for the nanometer IC design. In this thesis, we present an approach to statistically minimize the total power consumption on the 3D ICs by using the dual supply voltage technology. By Karhunen-Loeve expansion, the random processes of physical parameters such as the channel length and the oxide thickness with spatial correlations are transformed to a set of uncorrelated random variables. Since the leakage power on the chip is a random process due to the process variations, we employ a statistical thermal simulation method to get the mean and variance of temperature distribution. To emphasize the impact of temperature, the leakage current and gate delay models are temperature related and we implement a thermal aware statistical timing analysis method. The proposed power reduction approach uses power-delay sensitivity as the optimization criterion, and a grid-based method for handling the whole structure of the 3D ICs. Instead of executing statistical timing analysis every time, a potent concept is used in the algorithm to achieve the run time efficiency. The experimental results demonstrate the effectiveness of our method and indicate that considering the thermal effect in the circuit simulation is imperative.
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Chen, Jheng-De, and 陳鄭德. "Comparison of different capture parameters and process for ICC profile optimization." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/06283034062619215966.
Full textAbstract:
碩士<br>中國文化大學<br>資訊傳播學系<br>99<br>Digital image is formed by the light that reflected from the light source, through a lens and captured by the sensor as electronic signals. The color correction for device can be processed by mathematic models in different ways. Currently, the ICC profile is the most popular method in correcting color photographs.
The objective of this study is to test the performance of various ICC profiles that made from different procedures. The influence of various exposure settings, different build-in characteristic curves and a nonlinear correction method are also tested. The performance is evaluated by color difference value between the target color checker and its reproduction. It is intended to offer these results as a benchmark reference to ICC profile performance for color management on digital camera.
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Chen, Chin-Yaw, and 陳進曜. "Area and Maximal Wire-length Optimization of Analog ICs Layout Generator." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/48459410818384424877.
Full textAbstract:
碩士<br>國立中央大學<br>電機工程學系<br>101<br>Due to the sensitivity of analog components, and the size shrink of devices, post-layout electrical effects increasingly impact the circuit performance. In order to reduce the impact of electrical effects on circuits, the layout of analog circuits are mostly generated by manual. Although layouts of partial designs can be done by EDA tools with experience of engineers, to overcome the complex layout constraints and close to the regarded of engineers are the urgent issues.
Although there are many literatures on analog placement, the number of researches on analog placement considering routing is few. In the placement process, though we can use the topology constraints to reduce the mismatch, the unexpected electrical effects will be produced by the routing paths. In order to reduce the electrical effects produced by the routing paths, routing paths must avoid passing through the analog devices, and the maximal wire-length of routing must be shortened. Implying that to preserve enough routing spaces and limit wire-length in the placement stage are needed.
This work presents an analog placement and routing flow to handle the symmetry constraints, to preserve enough routing spaces, and to limit maximal wire-length between devices. Preserving the routing channels first, then using a two-stage curve pruning technology to trade-off between area and maximal wire-length. The flow is based on the deferred decision making (DDM) technique. Using DDM technique cannot only generate non-stochastic solutions, but also provide multiple and flexible solutions for engineers.
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Wang, Chien-Pei, and 王建培. "Optimization of Copper Wire Bonding Process of ICs Package by Taguchi Methods." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/j9xutz.
Full textAbstract:
碩士<br>國立中興大學<br>電機工程學系所<br>106<br>In recent years, due to the acceleration of the price of gold, the rapid development of the IC (Integrated Circuit) package copper process has become the mainstream of the packaging industry. This research is aimed at the copper package process to improve the packaging quality to shorten the time, indirectly reduce costs for the company.
This paper uses the Taguchi Methods to find the four control factors that affect the wire bonding process, bond power, bond time, bond force, bond temperature, with the L9 (34) orthogonal array, substrate with PBGA (Plastic Ball Grid Array) product analysis and empirical research, with the most influential quality of wire bonding processes as the object of discussion, copper wire process parameters via the Signal to Noise Ratio (S/N ratio) optimization.
After repeated verification and comparison with the original operating parameters, the experimental results obtained that the average value of the ball bond copper ball increased by 12.75%, the standard deviation decreased by 20.39%, the CpK increased by 59.51%, the IMC test increased by 12.05%, and the yield increased by 1.08%. The average value of the stitch bond copper wire increased by 16.43%, the standard deviation decreased by 36.78%, the CpK increased by 96.89%, and the yield increased by 1.08%. Finally, the copper parameters were optimized for three reliability tests (HAST, TCT, HTSL). Both are better than the original parameters and no product failure mode occurs. Not only has the experimental time been shortened, but it has also helped improve the copper process capability, greatly improved product quality, and achieved important improvement contributions.
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LI, Zhe. "Optimization of vido Delivery in Telco-CDN." Phd thesis, 2013. http://tel.archives-ouvertes.fr/tel-00808180.
Full textAbstract:
The exploding HD video streaming traffic calls for deploying content servers deeper inside network operators infrastructures. Telco-CDN are new content distribution services that are managed by Internet Service Providers (ISP). Since the network operator controls both the infrastructure and the content delivery overlay, it is in position to engineer Telco-CDN so that networking resources are optimally utilized. In this thesis, we focus on the optimal resource placement in Telco-CDN. We first investigated the placement of application components in Telco-CDN. Popular services like Facebook or Twitter, with a size in the order of hundreds of Terabytes, cannot be fully replicated on a single data-center. Instead, the idea is to partition the service into smaller components and to locate the components on distinct sites. It is the same and unique method for Telco-CDN operators. We addressed this k-Component Multi-Site Placement Problem from an optimization standpoint. We developed linear programming models, designed approximation and heuristic algorithms to minimize the overall service delivery cost. Thereafter, we extend our works to address the problem of optimal video place- ment for Telco-CDN. We modeled this problem as a k-Product Capacitated Facility Location Problem, which takes into account network conditions and users¿ prefer- ences. We designed a genetic algorithm in order to obtain near-optimal performances of such "push" approach, then we implemented it on the MapReduce framework in order to deal with very large data sets. The evaluation signifies that our optimal placement keeps align with cooperative LRU caching in term of storage efficiency although its impact on network infrastructure is less severe. We then explore the caching decision problem in the context of Information Cen- tric Network (ICN), which could be a revolutionary design of Telco-CDN. In ICN, routers are endowed with caching capabilities. So far, only a basic Least Recently Used (LRU) policy implemented on every router has been proposed. Our first contri- bution is the proposition of a cooperative caching protocol, which has been designed for the treatment of large video streams with on-demand access. We integrated our new protocol into the main router software (CCNx) and developed a platform that automatically deploys our augmented CCNx implementation on real machines. Ex- periments show that our cooperative caching significantly reduces the inter-domain traffic for an ISP with acceptable overhead. Finally, we aim at better understanding the behavior of caching policies other than LRU. We built an analytical model that approximates the performance of a set of policies ranging from LRU to Least Frequently Used (LFU) in any type of network topologies. We also designed a multi-policy in-network caching, where every router implements its own caching policy according to its location in the network. Compared to the single LRU policy, the multi-caching strategy considerably increases the hit- ratio of the in-network caching system in the context of Video-on-Demand application. All in one, this thesis explores different aspects related to the resource placement in Telco-CDN. The aim is to explore optimal and near-optimal performances of various approaches.
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Noia, Brandon Robert. "Design-for-Test and Test Optimization Techniques for TSV-based 3D Stacked ICs." Diss., 2014. http://hdl.handle.net/10161/8666.
Full textAbstract:
<p>As integrated circuits (ICs) continue to scale to smaller dimensions, long interconnects</p><p>have become the dominant contributor to circuit delay and a significant component of</p><p>power consumption. In order to reduce the length of these interconnects, 3D integration</p><p>and 3D stacked ICs (3D SICs) are active areas of research in both academia and industry.</p><p>3D SICs not only have the potential to reduce average interconnect length and alleviate</p><p>many of the problems caused by long global interconnects, but they can offer greater design</p><p>flexibility over 2D ICs, significant reductions in power consumption and footprint in</p><p>an era of mobile applications, increased on-chip data bandwidth through delay reduction,</p><p>and improved heterogeneous integration.</p><p>Compared to 2D ICs, the manufacture and test of 3D ICs is significantly more complex.</p><p>Through-silicon vias (TSVs), which constitute the dense vertical interconnects in a</p><p>die stack, are a source of additional and unique defects not seen before in ICs. At the same</p><p>time, testing these TSVs, especially before die stacking, is recognized as a major challenge.</p><p>The testing of a 3D stack is constrained by limited test access, test pin availability,</p><p>power, and thermal constraints. Therefore, efficient and optimized test architectures are</p><p>needed to ensure that pre-bond, partial, and complete stack testing are not prohibitively</p><p>expensive.</p><p>Methods of testing TSVs prior to bonding continue to be a difficult problem due to test</p><p>access and testability issues. Although some built-in self-test (BIST) techniques have been</p><p>proposed, these techniques have numerous drawbacks that render them impractical. In this dissertation, a low-cost test architecture is introduced to enable pre-bond TSV test through</p><p>TSV probing. This has the benefit of not needing large analog test components on the die,</p><p>which is a significant drawback of many BIST architectures. Coupled with an optimization</p><p>method described in this dissertation to create parallel test groups for TSVs, test time for</p><p>pre-bond TSV tests can be significantly reduced. The pre-bond probing methodology is</p><p>expanded upon to allow for pre-bond scan test as well, to enable both pre-bond TSV and</p><p>structural test to bring pre-bond known-good-die (KGD) test under a single test paradigm.</p><p>The addition of boundary registers on functional TSV paths required for pre-bond</p><p>probing results in an increase in delay on inter-die functional paths. This cost of test</p><p>architecture insertion can be a significant drawback, especially considering that one benefit</p><p>of 3D integration is that critical paths can be partitioned between dies to reduce their delay.</p><p>This dissertation derives a retiming flow that is used to recover the additional delay added</p><p>to TSV paths by test cell insertion.</p><p>Reducing the cost of test for 3D-SICs is crucial considering that more tests are necessary</p><p>during 3D-SIC manufacturing. To reduce test cost, the test architecture and test</p><p>scheduling for the stack must be optimized to reduce test time across all necessary test</p><p>insertions. This dissertation examines three paradigms for 3D integration - hard dies, firm</p><p>dies, and soft dies, that give varying degrees of control over 2D test architectures on each</p><p>die while optimizing the 3D test architecture. Integer linear programming models are developed</p><p>to provide an optimal 3D test architecture and test schedule for the dies in the 3D</p><p>stack considering any or all post-bond test insertions. Results show that the ILP models</p><p>outperform other optimization methods across a range of 3D benchmark circuits.</p><p>In summary, this dissertation targets testing and design-for-test (DFT) of 3D SICs.</p><p>The proposed techniques enable pre-bond TSV and structural test while maintaining a</p><p>relatively low test cost. Future work will continue to enable testing of 3D SICs to move</p><p>industry closer to realizing the true potential of 3D integration.</p><br>Dissertation
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Whi, Shu-Han, and 魏書含. "Power Optimization Method in 3D ICs Considering Thermal Effects – Dual Supply Voltage Assignment." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/84523505563178068303.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>98<br>The three dimensional integrated circuits (3D ICs) have been viewed as an effective
method to improve chip performance by overcoming the bottleneck of long
interconnects in the 2D ICs. However, the higher temperature becomes a serious
challenge for 3D ICs and mitigates the advantage of low power. Therefore, it is
important to propose an effective method considering thermal effect and power
optimization simultaneously. In this thesis, we present a methodology to minimize the
total power consumption in the 3D ICs by employing a dual supply voltage technique.
The proposed approach consider three main headings: 1) a voltage assignment process consider three main factor, which consists of sensitivity-based, proximity effect and level shifter budget factor, to be the voltage assignment criterion for power reduction; 2) a 3D electro-thermal simulation to get the temperature of chip; 3) a thermal aware static timing analysis to obtain the thermal-related delay of gate in the circuit. The experimental results demonstrate the effectiveness of our voltage assignment method and the thermal effect in circuit performance.
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Fikarová, Kateřina. "Set-up and optimization of automated in-syringe extraction of trace metals for ICP measurement." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-344047.
Full textAbstract:
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Kateřina Fikarová Supervisor: Burkhard Horstkotte, Ph.D., M.Sc. Consultant: Doc. PharmDr. Hana Sklenářová Ph.D. Work title: Set-up and optimization of automated in-syringe extraction of trace metals for ICP measurement The pollution of the environment by transition metals has to be monitored by sensitive methods due to the possible accumulation in humans and toxicity with respect to human health. For the first time, dispersive liquid-liquid extraction followed by back- extraction using the automation technique Lab-In-Syringe has been studied for the determination of Cd, Cu and Pb by inductive coupled plasma atomic emission spectrometry (ICP-AES). The method was automated using the void of a syringe pump of a sequential injection analysis (SIA) system as extraction vessel. A magnetic stirring bar was used for mixing the syringe's content and to disperse the extraction solvent. A motor holding neodymium magnets was used to force stirring rotation. Controlled by software, stirring could be stopped for phase separation. After setup and adjustment of the system and the operation procedure for automated extraction, preliminary experiments were done to evaluate the appropriate reagents....
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"Modeling and Optimization of a Hybrid Solar PV-Powered Air Conditioning System with Ice Storage." Master's thesis, 2011. http://hdl.handle.net/2286/R.I.14415.
Full textAbstract:
abstract: In this thesis the performance of a Hybrid AC System (HACS) is modeled and optimized. The HACS utilizes solar photovoltaic (PV) panels to help reduce the demand from the utility during peak hours. The system also includes an ice Thermal Energy Storage (TES) tank to accumulate cooling energy during off-peak hours. The AC runs continuously on grid power during off-peak hours to generate cooling for the house and to store thermal energy in the TES. During peak hours, the AC runs on the power supplied from the PV, and cools the house along with the energy stored in the TES. A higher initial cost is expected due to the additional components of the HACS (PV and TES), but a lower operational cost due to higher energy efficiency, energy storage and renewable energy utilization. A house cooled by the HACS will require a smaller size AC unit (about 48% less in the rated capacity), compared to a conventional AC system. To compare the cost effectiveness of the HACS with a regular AC system, time-of-use (TOU) utility rates are considered, as well as the cost of the system components and the annual maintenance. The model shows that the HACS pays back its initial cost of $28k in about 6 years with an 8% APR, and saves about $45k in total cost when compared to a regular AC system that cools the same house for the same period of 6 years.<br>Dissertation/Thesis<br>M.S. Mechanical Engineering 2011
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Tamasauskas, Justin. "Modeling and Optimization of a Solar Assisted Heat Pump Using Ice Slurry as a Latent Storage Material." Thesis, 2011. http://spectrum.library.concordia.ca/15141/1/Tamasauskas_MASc_F2011.pdf.
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Jain, Rupali. "Optimal Operation of Climate Control Systems of Indoor Ice Rinks." Thesis, 2012. http://hdl.handle.net/10012/7256.
Full textAbstract:
The electric power sector is undergoing significant changes with the development of Smart Grid technologies and is rapidly influencing the way we consume energy. Demand Response (DR) is an important element in the emerging smart grid paradigm and is paving way for the more sophisticated implementation of Energy Hub Management Systems (EHMSs). Utilities are looking at Demand Side Management (DSM) and DR services that allow customers to make informed decisions regarding their energy consumption which in return, can help the energy providers to reduce their peak demand and hence enhance grid sustainability.
Ice rinks are large commercial buildings which facilitate various activities such as hockey, figure skating, curling, recreational skating, public arenas, auditoriums and coliseums. These have a complex energy system; in which an enormous sheet of ice is maintained at a low temperature while at the same time the spectator stands are heated to ensure comfortable conditions for the spectators. Since indoor ice rinks account for a significant share of the commercial sector and are in operation for more than 8 months a year, their contribution in the total demand cannot be ignored. There is significant scope for energy savings in indoor ice rinks through optimal operation of their climate control systems.
In this work, a mathematical model of indoor ice rinks for the implementation of EHMS is developed. The model incorporates weather forecast, electricity price information and end-user preferences as inputs and the objective is to shift the operation of climate control devices to the low electricity price periods, satisfying their operational constraints while having minimum impact on spectator comfort. The inside temperature and humidity dynamics of the spectator area are modeled to reduce total electrical energy costs while capturing the effect of climate control systems including radiant heating system, ventilation system and dehumidification system. Two different pricing schemes, Real Time Pricing (RTP) and Time-of-Use (TOU), are used to assess the model, and the resulting energy costs savings are compared. The expected energy cost savings are evaluated for a 8 month period of operation of the rink incorporating the uncertainties in electricity price, weather conditions and spectator schedules through Monte Carlo simulations. The proposed work can be implemented as a supervisory control in existing climate controllers of indoor ice rinks and would play a significant role in the enforcement of EHMS in Smart Grids.
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Kwon, Tae-Jung. "SAR Remote Sensing of Canadian Coastal Waters using Total Variation Optimization Segmentation Approaches." Thesis, 2011. http://hdl.handle.net/10012/5893.
Full textAbstract:
The synthetic aperture radar (SAR) onboard Earth observing satellites has been acknowledged as an integral tool for many applications in monitoring the marine environment. Some of these applications include regional sea-ice monitoring and detection of illegal or accidental oil discharges from ships. Nonetheless, a practicality of the usage of SAR images is greatly hindered by the presence of speckle noises. Such noise must be eliminated or reduced to be utilized in real-world applications to ensure the safety of the marine environment. Thus this thesis presents a novel two-phase total variation optimization segmentation approach to tackle such a challenging task. In the total variation optimization phase, the Rudin-Osher-Fatemi total variation model was modified and implemented iteratively to estimate the piecewise smooth state by minimizing the total variation constraints. In the finite mixture model classification phase, an expectation-maximization method was performed to estimate the final class likelihoods using a Gaussian mixture model. Then a maximum likelihood classification technique was utilized to obtain the final segmented result. For its evaluation, a synthetic image was used to test its effectiveness. Then it was further applied to two distinct real SAR images, X-band COSMO-SkyMed imagery containing verified oil-spills and C-band RADARSAT-2 imagery mainly containing two different sea-ice types to confirm its robustness. Furthermore, other well-established methods were compared with the proposed method to ensure its performance. With the advantage of a short processing time, the visual inspection and quantitative analysis including kappa coefficients and F1 scores of segmentation results confirm the superiority of the proposed method over other existing methods.
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Wu, Tin-Hau, and 吳挺豪. "Optimization of an Ice-Storage Air Conditioning Load by Particle Swarm Algorithm for Reducing Energy Consumption and CO2 Emission." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/9e2e9q.
Full textAbstract:
碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>96<br>Utilizing the feature of charge-at-night and discharge-in-daytime to transfer peak power
consumption to off-peak hours for reducing the peak load during the day, ice-storage air
conditioning system has become increasingly important as the problem of energy
shortage keeps aggravating. However, poor design and failure to consider the operational
features of the main chiller, ice storage tank and related auxiliary equipment can prevent
an ice-storage air-conditioning system from generating the needed cold energy and
facilitating the desired power saving.The study accordingly aims at developing and
optimal mathematical model for the operation of ice-storage air-conditioning system
adopting energy operating cost as the target function and the performance of the main
chiller and ice-storage tank as the limitation. A Particle Swarm optimization algorithm is
used to measure the optimal ice melting capacity during the daytime and the ice storage
capacity . The study further analyzes and compares the system’s life-cycle cost .
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Isaac, Tobin Gregory. "Scalable, adaptive methods for forward and inverse problems in continental-scale ice sheet modeling." Thesis, 2015. http://hdl.handle.net/2152/31372.
Full textAbstract:
Projecting the ice sheets' contribution to sea-level rise is difficult because of the complexity of accurately modeling ice sheet dynamics for the full polar ice sheets, because of the uncertainty in key, unobservable parameters governing those dynamics, and because quantifying the uncertainty in projections is necessary when determining the confidence to place in them. This work presents the formulation and solution of the Bayesian inverse problem of inferring, from observations, a probability distribution for the basal sliding parameter field beneath the Antarctic ice sheet. The basal sliding parameter is used within a high-fidelity nonlinear Stokes model of ice sheet dynamics. This model maps the parameters "forward" onto a velocity field that is compared against observations. Due to the continental-scale of the model, both the parameter field and the state variables of the forward problem have a large number of degrees of freedom: we consider discretizations in which the parameter has more than 1 million degrees of freedom. The Bayesian inverse problem is thus to characterize an implicitly defined distribution in a high-dimensional space. This is a computationally demanding problem that requires scalable and efficient numerical methods be used throughout: in discretizing the forward model; in solving the resulting nonlinear equations; in solving the Bayesian inverse problem; and in propagating the uncertainty encoded in the posterior distribution of the inverse problem forward onto important quantities of interest. To address discretization, a hybrid parallel adaptive mesh refinement format is designed and implemented for ice sheets that is suited to the large width-to-height aspect ratios of the polar ice sheets. An efficient solver for the nonlinear Stokes equations is designed for high-order, stable, mixed finite-element discretizations on these adaptively refined meshes. A Gaussian approximation of the posterior distribution of parameters is defined, whose mean and covariance can be efficiently and scalably computed using adjoint-based methods from PDE-constrained optimization. Using a low-rank approximation of the covariance of this distribution, the covariance of the parameter is pushed forward onto quantities of interest.
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Ochilov, Shuhratchon. "A New Look Into Image Classification: Bootstrap Approach." Thesis, 2012. http://hdl.handle.net/10012/6587.
Full textAbstract:
Scene classification is performed on countless remote sensing images in support of operational activities. Automating this process is preferable since manual pixel-level classification is not feasible for large scenes. However, developing such an algorithmic solution is a challenging task due to both scene complexities and sensor limitations. The objective is to develop efficient and accurate unsupervised methods for classification (i.e., assigning each pixel to an appropriate generic class) and for labeling (i.e., properly assigning true labels to each class). Unique from traditional approaches, the proposed bootstrap approach achieves classification and labeling without training data. Here, the full image is partitioned into subimages and the true classes found in each subimage are provided by the user. After these steps, the rest of the process is automatic. Each subimage is individually classified into regions and then using the joint information from all subimages and regions the optimal configuration of labels is found based on an objective function based on a Markov random field (MRF) model. The bootstrap approach has been successfully demonstrated with SAR sea-ice and lake ice images which represent challenging scenes used operationally for ship navigation, climate study, and ice fraction estimation. Accuracy assessment is based on evaluation conducted by third party experts. The bootstrap method is also demonstrated using synthetic and natural images. The impact of this technique is a repeatable and accurate methodology that generates classified maps faster than the standard methodology.